1. Field of the Invention
This invention relates to a disk plate for a disk drive. More particularly, this invention relates to a plate body of the disk plate being attached to a fixed spindle shaft of a spindle motor.
2. Description of the Prior Art and Related Information
A huge market exists for disk drives such as hard disk drives for mass-market host computer systems such as servers, desktop computers, and laptop computers. To be competitive in this market, a hard disk drive must be relatively inexpensive, and must accordingly embody a design that is adapted for low-cost mass production. In addition, it must provide substantial capacity, rapid access to data, and reliable performance. Numerous manufacturers compete in this huge market and collectively conduct substantial research and development, at great annual cost, to design and develop innovative hard disk drives to meet increasingly demanding customer requirements.
Each of numerous contemporary mass-market hard disk drive models provides relatively large capacity, often in excess of 40 gigabytes per drive. Nevertheless, there exists substantial competitive pressure to develop mass-market hard disk drives that have even higher capacities and that provide rapid access. Another requirement to be competitive in this market is that the hard disk drive must conform to a selected standard exterior size and shape often referred to as a “form factor.” Generally, capacity is desirably increased without increasing the form factor or the form factor is reduced without decreasing capacity.
Satisfying these competing constraints of low-cost, small size, high capacity, and rapid access requires innovation in each of numerous components and methods of assembly including methods of assembly of various components into certain subassemblies. Typically, the main assemblies of a hard disk drive are a head disk assembly and a printed circuit board assembly.
The head disk assembly includes an enclosure including a base and a cover, at least one disk having at least one recording surface, a spindle motor for causing each disk to rotate, and an actuator arrangement. The printed circuit board assembly includes circuitry for processing signals and controlling operations. Actuator arrangements can be characterized as either linear or rotary; substantially every contemporary cost-competitive small form factor drive employs a rotary actuator arrangement.
Another requirement to be competitive in this market is that the hard disk drive must be relatively quiet, especially in applications such as the consumer electronics market. One contributor to the acoustic noise generated by a hard disk drive is the structural vibration of a fixed spindle shaft motor, which is transmitted to a disk drive cover. Structural vibrations are caused by the eccentric motion, gyroscopic motion, and/or axial motion of the fixed spindle shaft motor. Spindle motors may have either a non-rotating spindle shaft (“fixed spindle shaft”) or a rotating spindle shaft.
In a spindle motor having a fixed spindle shaft (“fixed spindle shaft motor”), the fixed spindle shaft is typically attached to the disk drive cover via a suitable fastener such as a screw. In such an arrangement, the structural vibrations of such fixed spindle shaft motors are transmitted to the disk drive cover when the spindle motor rotates during an operation of the hard disk drive. Hence, the disk drive cover vibrates which contribute to the acoustic noise generated by the hard disk drive.